Composite fuse holders

ABSTRACT

Fuse holders having insulating bases fabricated mainly of extruded or pultruded sections which are preferably adhesively bonded together. Polyphase fuse holders of this description include interphase barriers clamped in position by bases between which they are arranged and adhesively bonded to these bases.

United States Patent 1 Salzer et a].

[ Dec. 23, 1975 COMPOSITE FUSE HOLDERS [75] Inventors: Erwin Salzer, Waban, Mass; Frederick J. Kozacka, South Hampton, NH.

[73] Assignee: The Chase-Shawmut Company,

Newburyport, Mass.

[22] Filed: Nov. 1, 1974 [21] Appl. No.: 519,918

[52] US. Cl. 339/125 R; 339/198 G; 339/258 F;

337/213 [51] Int. Cl. ..H01R 9/12 [58] Field of Search 339/125, 198, 219, 252,

[56] References Cited UNITED STATES PATENTS 2,990,534 6/1961 Nielsen 339/198 GA 3,810,077 5/1974 Salzer 339/219 F FOREIGN PATENTS OR APPLICATIONS 1,114,570 10/1961 Germany 1. 339/258 F Primary Examiner-Joseph H. McGlynn Attorney, Agent, or Firm-Erwin Salzer 5 7 ABSTRACT Fuse holders having insulating bases fabricated mainly of extruded or pultruded sections which are preferably adhesively bonded together.

Polyphase fuse holders of this description include interphase barriers clamped in position by bases between which they are arranged and adhesively bonded to these bases.

12 Claims, 6 Drawing Figures U.S. Patent Dec. 23, 1975 Sheet 1 of2 3,927,927

FIG.3

COMPOSITE FUSE HOLDERS BACKGROUND OF THE INVENTION In recent years there have been two opposite trends in the development of electric fuses. On the one hand, there has been a trend toward standarization of design to limit the cost of production and, on the other hand, there has been a trend toward diversification of design in order to meet the progressive diversification of required performance characteristics. Both trends are viable, each within specific limits. The trend toward diversification of design resulted in the evolution of various fuse structures which can be formed by combining in different ways a relatively limited number of standardized parts. The diversification in regard to the design of fuses ought to be followed by a diversification as to the design of fuse holders. Such fuse holders must be designed in such a fashion as to allow formation of a great variety of fuse holder structures by combining in different ways a relatively limited number of standardized parts.

This sound approach has been tried in the past, but as yet with a very limited degree of success.

It is, therefore, one object of this invention to provide a building-block-kit-like system of parts which can readily be assembled to form a great variety of fuse holders.

Another object of this invention is to form such a system of extruded or pultruded parts since such parts are easier and less expensive to produce than molded parts, and since the use of such parts is conducive to a greater variety of possible combinations.

Still another object of this invention is to provide fuse holders fabricated of extruded or pultruded sections which are adhesively bonded together and lend themselves by virtue of their geometry to be joined together by structural adhesives.

. SUMMARY OF THE INVENTION Fuse holders embodying this invention include a pair of fuse-receiving contacts and a pair of aligned spaced supports of synthetic resin for said pair of contacts. Each of said pair of supports has a web portion supporting one of said pair of contacts and each of said pair of supports has lateral flange portions projecting at substantially right angles from said web portion thereof. Fuse holders embodying this invention further include a tie member of a synthetic resin having surfaces telescopically mating with. and adhesively affixed to, said lateral flange portions of said pair of supports.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a diagrammatic isometric representation of a fuse holder embodying this invention and of a fuse that is supported by it;

FIG. 2 is a side elevation ofa structure similar to that shown in FIG. I;

FIG. 3 is an end view of the structure of FIG. 2;

FIG. 4 is a bottom-plan view of the fuse holder shown in FIG. 2;

FIG. 5 is an end view of a polyphase fuse holder embodying this invention; and

FIG. 6 is a top-plan view of the fuse holder of FIG. 5, one end portion of it being broken away.

DESCRIPTION OF PREFERRED EMBODIMENTS Referring now to the drawings, and more particularly to FIG. 1 thereof, numeral 1 has been applied to gener ally designate a pair of fuse-receiving contacts. These contacts I have been shown but diagrammatically in FIG. 1. Each contact I includes a tang I from which two resilient contact jaws I" project in upward direction. FIG. I shows but one of the two resilient contact jaws I" forming part of each contact I, the other contactjaw being broken away to better expose to view the two blade contacts 2' of a fuse generally designated by the reference numeral 2. Reference numeral 3 has been applied to designate a pair of aligned spaced supports of synthetic resin, preferably a thermosetting resin, for contacts I. Each of supports 3 is substantially in the shape of an inverted channel section including the web portion 3' supporting one of contacts I and the lateral flange portions 3" projecting at substantially right angles from web portion 3'. The support 3 are tied together by a tie member generally indicated by numeral 4 which is substantially in the shape of a channel having a web portion 4' and flange portions 4". The ends of tie member 4 are telescoped into supports 3 and the flanges 4" of tie member 4 mate with the flanges 3" of supports 4 and are adhesively affixed to each other.

An adhesive bond is, in fact, a very large number of spaced discrete bonds and so appears when viewed at considerable magnification. The larger the number of discrete, or individual bonds, the greater the strength of the joint and the durability thereof. The larger the area of the lap, the better the performance characteristics of the adhesive bond and the fuse holders embodying this invention were evolved with this in mind.

In FIGS. 2-4 the same reference characters as in FIG. 1 with an a added have been applied to designate like parts. Hence the structure of FIGS. 2-4 may be described more or less summarily.

Referring now to FIGS. 2-4, the channel-shaped contact supports 3a support with their web portions 3'a thereof a pair of fusesupporting contacts Ia. Contacts la are engaged by the blade contacts 2'a of a fuse 2a. The tangs I'a of contacts Ia project beyond supports 3a axially outwardly. Supports 3a are tied together by channel-shaped tie member 4a of synthetic resin having a web portion 4'a and flange portions 4' a. The flat web portion 4'a of tie member 4a is provided with a pair of perforations 4"a for attaching the fuse holder by means of fasteners such as, for instance, screws, to a steel plate 5a or the like fuse-hoIder-supporting frame structure.

The surfaces of tie member 4a telescopically mating with the lateral flange portions 3"a of supports 3a are located on the inner sides of flange portions 3"a of supports 3a leaving the outer surfaces of flange portions 3"a unencumbered. In other words, the outer surfaces of flange portions 4"a of tie member 4a mate with the inner surfaces of flange portions 3"a of supports 3a.

The lengths of the telescoping mating engagement of the tie member 4a by supports 3a is substantially equal. or exactly equal, to the sum of the length of each of supports 30. In FIG. 4 the length of each of the pair of supports 3a has been designated by the reference character 8. It is desirable in the interest of maximizing the dimensional stability of the fuse holder structure to extend tie member 4a from the axially inner edges of supports 3a all the way to the axially outer edges thereof.

It will be apparent from FIGS. 2-4 that the width W of the flange portions 3"a exceeds the width w of the flange portions 4"a. This condition must be met so that the edges of web portions 3"a of supports 3 and the outer surface of the web portion 4'a of tie member 4a may be co-planar.

Referring now to FIGS. 5 and 6, the three phase fuse holder shown therein includes three pairs of contacts 10R, ")8, WT. In FIGS. 5 and 6 some portions of these contacts are broken away. The structure of FIGS. 5 and 6 further includes three pairs of aligned spaced substantially channel-shaped supports of synthetic resin for the three pairs of contacts IOR, 105, I01. Reference characters IIR, IIS, llT have been applied to indicate the six channel-shaped contact supports forming the aforementioned three pairs of supports. Each of supports 11R, I IS, [IT has a web portion 11"R, 11"8, 11"T supporting one of contacts .l0R, I08, 101 and flange portions ll"R, 11"S, II"T. The outer surfaces of flange portions ll"R, II"S, ll"T include nonrecessed areas NRA and recessed areas RA recessed behind the non-recessed areas NRA. The structure of FIGS. 5 and 6 further includes three channel-shaped tie member TR, TS, TT of synthetic resin. Tie members TR mates telescopically with the inner surfaces of the flange portions II"R of the pair of contact supports 11R, and is affixed to said flange portions. Tie members TS and TT are likewise of synthetic resin. The former mates telescopically with the inner surfaces of the flange portions "5 of the pair of supports 11S and is affixed to said flange portions. The latter mates telescopically with the inner surfaces of the flange portions 11"T of the pair of supports UT and is affixed to said flange portions. Tie member TR is preferably adhesively bonded to supports 11R, tie member TS is preferably adhesively bonded to supports 11S, and tie member TT is preferably adhesively bonded to supports IIT.

It will be apparent from a comparison of FIGS. 3 and 5 that in the former channel members 3 and 4 are not mechanically interlocked, while in the latter channel members 3a and 5a are mechanically interlocked. Where there is such a mechanical interlock the task of affixing the contact supports to the tie members is facilitated. Thus in the structure of FIGS. 5 and 6 parts TR, TS and TT must not necessarily be bonded adhesively to parts "R, US and UT. The adhesive bond may be substituted, if desired, by a small mechanical fastener (not shown). Parts HR, 118 and HT and TR, TS, TT may be sufficiently resilient to be snapped together and held by friction in their position.

As shown in FIG. 6 the tie members TR, TS and TT are each provided with a pair of perforations P, P for affixing the fuse holder to an appropriate support as, for instance, a steel plate such as that shown in FIGS. 2, 3 and 4 at 50.

It will be apparent from FIG. 5 that non-recessed areas NRA of channel-shaped contact supports HR, 118, IIT abut against each other and that recessed areas RA of channel-shaped contact supports HR, 118, HT form elongated cavities between contiguous channel-shaped contact supports HR, 115, UT. The aforementioned non-recessed areas may be used to join contiguous channel-shaped contact supports HR, 118, IIT into integral structural units, e.g., adhesive bonding. Since the tie members TR, TS, TT are affixed to 4 supports 11R, IIS, I IT, three tie members TR, TS, TT and six contact supports 11R, IIS, llT form an integral or self-sustained structural unit when properly affixed to each other.

In FIGS. 5 and 6 reference characters BR have been applied to indicate interphase barriers of electric insulating material separating the contact means 10R, [08, 101 which are at different potentials from each other. The barriers BR include upper portions projecting above the web portions II"R, ll"S and ll"T of contact supports 11R, IIS, 111. The barriers BR further include lower portions arranged below the web portions 11"R, ""8 and II"T of contact supports HR, 118, IIT. The lower portions ofinterphase barriers BR are inserted or telescoped into the gaps bounded by the recessed areas RA of the flange portions II"R, II"S, II"T of contact supports 1 IR, 115, 1 IT.

The non-recessed areas NRA of flange portions 11"R, 11"S, II"T are preferably planar and used to bond contact supports HR, US, 111 to each other.

The recessed areas RA of flange portions II"R, I I"S, ll"T of contact supports HR, 118, 111 include curved surface elements having straight generatrices. This greatly facilitates the manufacture of parts IIR, II"S, 11"T and of parts "R, US, "T, the assembly thereof, and achieves an effective interlocking action between these parts. The interphase barriers BR may be simply telescoped into the elongated cavities bounded by recessed areas RA and firmly held therein by a minimal quantity of structural adhesive.

It will be understood that the three phase fuse holder shown in FIGS. 5 and 6 may be readily converted into a two phase fuse holder by deleting one of the three phase units and one pair of interphase barriers BR. The structure shown in FIGS. 5 and 6 may also be adapted as single phase fuse holder and if so adapted is more desirable than the structure shown in FIGS. 1-4 because of the mechanical interlocking action ofits channel-shaped parts.

The channel-shaped contact supports and the channel-shaped tie members are preferably made of pultruded gIass-fiber-filled polyester. The weight of such fuse holders is far less than that of comparable fuse holders including solid blocks of ceramic insulation, asbestos cement, etc. Such weight reduction is highly desirable under all circumstances. In most instances fuse holders as shown above are factory assembled and factory combined to form distribution panels. There are, however, also instances requiring substitution in the field of one fuse holder for another as, for instance, where a fuse holder having no rejection feature ought to be substituted for a fuse holder rejecting low interrupting capacity fuses and admitting only high interrupting capacity fuses. Considering such instances, the back of the tie members may be coated with a pressure sensitive adhesive, normally covered with a protective sheet of paper. The presence of such pressure sensitive adhesive coating coupled with the small weight of the fuse holder allows the same to be tacked temporarily in place on a vertical wall before being permanently affixed to the latter by fasteners, e.g., screws, projecting through perforations 4"a (FIG. 2) and P (FIG. 6) respectively. of the tie member.

We claim as our invention:

1. A fuse holder for electric fuses comprising a. a pair of fuse-receiving contacts;

b. a pair of aligned spaced supports of synthetic resin for said pair of contacts each having a web portion supporting one of said pair of contacts. and each having lateral flange portions projecting at substantially right angles from said web portion thereof: and c. a tie member of a synthetic resin having surfaces telescopically mating with and adhesively affixed to, said lateral flange portions of said pair of supports.

2. A fuse holder as specified in claim 1 wherein said tie member includes a flat perforated bottom portion extending substantially parallel to said web portion of each of said pair of supports.

3. A fuse holder as specified in claim 1 wherein the telescopically mating surfaces of said pair of supports and of said tie member are non-planar.

4. A fuse'holdcr as specified in claim I wherein said surfaces of said tie member telescopically mating with said lateral flange portions of said pair of supports are located on the inner sides of said flange portions of said pair of supports.

5. A fuse holder as specified in claim 3 wherein the length of telescopic mating of said tie member and said pair of supports is substantially equal to the sum of the length of each of said pair of supports.

6. A fuse holder as specified in claim 1 wherein a. said pair of supports and said tie member are substantially channel-shaped;

b. the width of the flange portions of said pair of supports exceeds the width of the flange portions of said tie member; and wherein c. the flange portions of said tie member which telescopically mate with the flange portions of said pair of supports are situated on the insides of said flange portions of said pair of supports.

7. A fuse holder as specified in claim 6 wherein said telescopically mating flange portions of said tie member and of said pair of supports include curved surface elements having straight generatrices extending in a direction longitudinally of said tie member.

8. A fuse holder for electric fuses comprising a. a pair of fuse receiving contacts;

b. a pair of aligned spaced substantially channelshaped supports of glass-fiber-filled polyester for said pair of contacts each having a web portion supporting one of said pair of contacts and each having a pair of lateral flange portions;

c. a tie member of a synthetic resin having surfaces overlapping and mating with conforming inner surfaces of said lateral flange portions of said pair of supports and maintaining said pair of supports in a fixed predetermined distance; and

d. wherein the mating and overlapping surfaces of b. a first pair of aligned spaced supports of synthetic resin for said first pair of contacts. each of said first pair of supports having a web portion supporting one of said first pair of contacts and flange portions, the outer surfaces of said flange portions including non-recessed areas and recessed areas recessed behind said non-recessed areas;

c. a first tie member of synthetic resin which mates telescopically with the inner surfaces of said flange portions of said first pair of supports and is affixed to said flange portions thereof;

d. a second pair of fuse-receiving contacts;

e. a second pair of aligned spaced supports of syn thetic resin for said second pair ofcontacts, each of said second pair of supports having a web portion supporting one of said second pair of contacts and flange portions, the outer surfaces of said flange portions including non-recessed areas and recessed areas recessed behind said non-recessed areas;

f. a second tie member of synthetic resin which mates telescopically with the inner surfaces of said flange portions of said second pair of supports and is affixed to said flange portions thereof;

g. said first pair of supports and said second pair of supports being arranged in abutting relation with non-recessed areas of said flange portions thereof and affixed to each other; and

h. a pair of interphase barriers including upper portions projecting above said web portions of said first pair of supports and said web portions of said second pair of supports and said pair of interphase barriers further including lower portions arranged below said web portions of said first pair of supports and said web portions of said second pair of supports, said lower portions of said pair of interphase barriers being inserted into gaps bounded by said recessed areas of said flange portions of said first pair of supports and said recessed areas of said flange portions of said second pair of supports.

10. A polyphase fuse holder as specified in claim 9 wherein a. said first pair of supports and said tie member are adhesively affixed to each other;

said second pair of supports and said second tie member are adhesively affixed to each other;

c. said first pair of supports and said second pair of supports are adhesively affixed to each other; and wherein d. said lower portions of said pair of interphase barriers are adhesively affixed to said first pair of supports and to said second pair of supports.

11. A fuse holder as specified in claim 9 wherein said non-recessed areas of said flange portions of said first pair of supports and said non-recessed areas of said flange portions of said second pair of supports are planar.

[2. A fuse holder as specified in claim ll wherein said recessed areas of said flange portions of said first pair of supports and said recessed areas of said flange portions of said second pair of supports include curved surface elements having straight generatrices. 

1. A fuse holder for electric fuses comprising a. a pair of fuse-receiving contacts; b. a pair of aligned spaced supports of synthetic resin for said pair of contacts each having a web portion supporting one of said pair of contacts, and each having lateral flange portions projecting at substantially right angles from said web portion thereof: and c. a tie member of a synthetic resin having surfaces telescopically mating with, and adhesively affixed to, said lateral flange portions of said pair of supports.
 2. A fuse holder as specified in claim 1 wherein said tie member includes a flat perforated bottom portion extending substantially parallel to said web portion of each of said pair of supports.
 3. A fuse holder as specified in claim 1 wherein the telescopically mating surfaces of said pair of supports and of said tie member are non-planar.
 4. A fuse holder as specified in claim 1 wherein said surfaces of said tie member telescopically mating with said lateral flange portions of said pair of supports are located on the inner sides of said flange portions of said pair of supports.
 5. A fuse holder as specified in claim 3 wherein the length of telescopic mating of said tie member and said pair of supports is substantially equal to the sum of the length of each of said pair of supports.
 6. A fuse holdeR as specified in claim 1 wherein a. said pair of supports and said tie member are substantially channel-shaped; b. the width of the flange portions of said pair of supports exceeds the width of the flange portions of said tie member; and wherein c. the flange portions of said tie member which telescopically mate with the flange portions of said pair of supports are situated on the insides of said flange portions of said pair of supports.
 7. A fuse holder as specified in claim 6 wherein said telescopically mating flange portions of said tie member and of said pair of supports include curved surface elements having straight generatrices extending in a direction longitudinally of said tie member.
 8. A fuse holder for electric fuses comprising a. a pair of fuse receiving contacts; b. a pair of aligned spaced substantially channel-shaped supports of glass-fiber-filled polyester for said pair of contacts each having a web portion supporting one of said pair of contacts and each having a pair of lateral flange portions; c. a tie member of a synthetic resin having surfaces overlapping and mating with conforming inner surfaces of said lateral flange portions of said pair of supports and maintaining said pair of supports in a fixed predetermined distance; and d. wherein the mating and overlapping surfaces of said tie member and of said pair of supports include curved surface elements having straight generatrices extending in a direction longitudinally of said tie member.
 9. A polyphase fuse holder including a. a first pair of fuse-receiving contacts; b. a first pair of aligned spaced supports of synthetic resin for said first pair of contacts, each of said first pair of supports having a web portion supporting one of said first pair of contacts and flange portions, the outer surfaces of said flange portions including non-recessed areas and recessed areas recessed behind said non-recessed areas; c. a first tie member of synthetic resin which mates telescopically with the inner surfaces of said flange portions of said first pair of supports and is affixed to said flange portions thereof; d. a second pair of fuse-receiving contacts; e. a second pair of aligned spaced supports of synthetic resin for said second pair of contacts, each of said second pair of supports having a web portion supporting one of said second pair of contacts and flange portions, the outer surfaces of said flange portions including non-recessed areas and recessed areas recessed behind said non-recessed areas; f. a second tie member of synthetic resin which mates telescopically with the inner surfaces of said flange portions of said second pair of supports and is affixed to said flange portions thereof; g. said first pair of supports and said second pair of supports being arranged in abutting relation with non-recessed areas of said flange portions thereof and affixed to each other; and h. a pair of interphase barriers including upper portions projecting above said web portions of said first pair of supports and said web portions of said second pair of supports and said pair of interphase barriers further including lower portions arranged below said web portions of said first pair of supports and said web portions of said second pair of supports, said lower portions of said pair of interphase barriers being inserted into gaps bounded by said recessed areas of said flange portions of said first pair of supports and said recessed areas of said flange portions of said second pair of supports.
 10. A polyphase fuse holder as specified in claim 9 wherein a. said first pair of supports and said tie member are adhesively affixed to each other; said second pair of supports and said second tie member are adhesively affixed to each other; c. said first pair of supports and said second pair of supports are adhesively affixed to each other; and wherein d. said lower portions of said pair of interphase barriers are adhesively affixed to said first pair of supports and to said second pair of supports.
 11. A fuse holder as specified in claim 9 wherein said non-recessed areas of said flange portions of said first pair of supports and said non-recessed areas of said flange portions of said second pair of supports are planar.
 12. A fuse holder as specified in claim 11 wherein said recessed areas of said flange portions of said first pair of supports and said recessed areas of said flange portions of said second pair of supports include curved surface elements having straight generatrices. 